The wife of fallen former Interpol chief Meng Hongwei has expressed fears for his life and her own safety, lashing out at what she called the "cruel" and "dirty" Chinese government that arrested him in mysterious circumstances.

The comments by Grace Meng in a BBC interview represent a rare and extraordinarily blunt level of criticism of China's government by the victims of Beijing's tough crackdown on corruption, in which cases are typically wrapped up in secrecy and with only the official version of events coming to light.

"I think it is political persecution. I'm not sure he's alive," Grace Meng said in the interview conducted in France, where Meng was based at Interpol's headquarters.

Meng Hongwei, also a Chinese vice public security minister, went missing on a trip to China last month. He subsequently resigned as head of the international police organisation on Oct 7 after Chinese authorities announced he was under investigation.